Jennifer Aniston & Justin Theroux: From Telluride to Purgatory

From left: Justin Theroux, Jason Baldwin, Joe Berlinger, Orlando Bloom and Jennifer Aniston

Just after Jennifer Aniston and Justin Theroux returned from 10 days together in Telluride, they got back to the business they love most: movies. 

The Wanderlust costars, who have been romantically linked since May, attended Monday's HBO screening of Paradise Lost 3: Purgatory. 

The couple flanked Jason Baldwin, director Joe Berlinger and fellow actor Orlando Bloom for a photo at L.A.'s Ray Kurtzman Theater, within the Creative Artists Agency. 

"They were very sweet and social as always. They're really comfortable with each other," an onlooker tells PEOPLE. "Seemed like just another night on the town."